Cyclic sewing machine



Dec. 9, 1969 SHIGEKI HAYASHI ET 3,482,535

CYCLIC SEWING MACHINE Filed June 12, 1967 8 Sheets-Sheet 1 N ,wfmw 16 M4744 444 INVENTORS Bud/0&4 M,

Dec. 9, 1969 sH|GEK| HAYASHl ET AL 3,482,535

CYCLIC SEWING MACHINE 8 Sheets-Sheet 2 Filed June 12, 1967 1 Dec. 9,1969 'SHIGEKI HAYASHI ET AL 3,482,535

CYCLIC SEWING MACHINE Filed June 12, 1967 8 Sheets-Sheet 3 INVENTORS D1969 SHIGEKIAHAYASHI ET AL 3,482,535

' CYCLIC SEWING MACHINE Filed June 12, 1967 8 Sheets-Sheet 4 VI 22(35)"1 K i I I i I 2 INVENTORS dwxggi D 9, 1959 I SHIGEKI HAYASHI ET A3,482,535

CYCLIC SEWING MACHINE Filed June 12, 1967 8 Sheets-Sheet 5 1 5| 1% H I43 l, O

57 5 43 r I X J 1 O INVENTORS' De. 9, 1969 SHIGEKI HAYASHI fiTAL3,432,535

CYCLIG SEWING MACHINE Filed June 12, 1967 8 Sheets-Sheet 6 Dec. 9, 1969SH|GEK| -u ET AL 3,482,535

CYCLIC SEWING MACHINE Filed June 12, 1967 s Sheets-Shet '7 l INVENTORS'Dec. 9, 1 369 smsm HAYASHI ET'AL 3,482,535

7 CYCLIC SEWING MACHINE Filed June 12, 1967 8 Sheets-Sheet 8' vINVENTORY UM/ 77 M United States Patent 3,482,535 CYCLIC SEWING MACHINEShigeki Hayashi and Hiroaki Shinomiya, Fuchu-shi, and Hideaki Kobayashi,Chofu-shi, Japan, assignors to Tokyo Juki Kogyo Kabushiki Kaisha FiledJune 12, 1967, Ser. No. 645,415 Int. Cl. Db 3/00; F16d 21/00 U.S. Cl.112-67 5 Claims ABSTRACT OF THE DISCLOSURE A cyclic sewing machine inwhich the machine actuating and shut-01f mechanism and the presser footcontrol mechanism are so arranged that after the presser foot has beenlowered to its predetermined operative position for holding down thematerial to be sewn, the machine is actuated and after a desired seamhas been formed the machine automatically stops and then the presserfoot is raised to the initial inoperative position and in response tothe upward movement of the presser foot the thread cut-off blade isactuated to cut the thread off.

BACKGROUND OF THE INVENTION In a conventional cyclic sewing machine,generally two separate manually operated pedals are provided and one ofthe pedals is adapted to actuate a mechanism which in turn actuates themachine and raises the needle to a predetermined upper inoperativeposition to set the same in said position (the mechanism will bereferred to as shut-off mechanism herein) while the other pedal isadapted to actuate a mechanism which in turn moves the presser footupwardly and downwardly independently of the shut-off mechanism. Theoperation of the shut-off mechanism and the presser foot controlmechanism should be repeated each time a cycle of the sewing operationis performed for each seam to be formed in the material to be sewn andaccordingly, when it is desired or necessary to form a number of seamsin the material successively, the operator has to respect operation ofboth the mechanisms the corresponding number of times requiringconsiderable labor and the operator becomes fatigued quickly resultingin a lowered operation efficiency. Furthermore, the operation of theshut-ofi" mechanism and presser foot control mechanism in apredetermined timed relation requires skilled operators. In addition,after a cycle of thsewing operation, when the needle is not set in thepredetermined upper inoperative position due to trouble in the shut-offmechanism and remains in position in the material or stops halfwaybetween the predetermined upper and lower limits of its movement, if theoperator raises the presser foot carelessly, the thread cut-off blade,which is adapted to operate in response to the upward movement of thepresser foot, may strike against and break or damage the needle.

Another conventional cyclic sewing machine includes manually operatedswitches, relays operated by some of the switches, further switchesactuated by the relays, switches for actuating and stopping the machine,two magnets operative in response to the closing and opening of all theswitches and relays, two shafts adapted to intermittently rotate inresponse to the energizing and deenergizing of the magnets and in whichthe two shafts are rotated in such a timed relation that one of theshafts first lowers the presser foot to an intermediate position betweenthe predetermined upper and lower limits of its movement and then afterthe machine has been precisely positioned relative to the material to besewn, further lowers the pressure foot to the predetermined lower limitor material holding-down position, whereupon the machine is actuated.After a cycle of operation has been completed the 'ice machine isstopped and at the same time the presser foot is returned to thepredetermined upper limit position. However, in such a conventionalcyclic sewing machine, in order to ascertain whether or not the pressurefoot is in a correct position with respect to a portion of the materialwhere a seam is formed the presser foot has to be temporarily suspendedmidway between the predetermined upper and lower limits of its movementabove the portion of the material and accordingly, it is not easy toprecisely align the presser foot with the portion of the material. Ifthe presser foot is directly lowered to the lower limit or materialholding-down position in order to align the presser foot with theportion of the material, since the machine is adapted to be actuated assoon as the presser foot has been lowered to the material holdingposition, it is difficult to align the presser foot with the portion ofthe material. Since the switches are so arranged that they raise thepresser foot to the predetermined upper limit as soon as a seam has beenformed in the material portion, if the thread breaks during the time theseam is being formed, the particular cycle of operation will finishwithout forming a complete seam and the presser foot is raised to theupper limit position. In this case the material will be dislocated andaccordingly, a complete seam or a length of continuously stitched seamcannot be obtained.

SUMMARY OF THE INVENTION The present invention relates to a novel cyclicsewing machine suitable for forming button holes and like operations,and more particularly to the control mechanism for such a sewing machinewhereby the machine actuating and shut-off mechanism and the presserfoot control mechanism are operated in such a timed relation that afterthe presser foot has been positively lowered to a correct position onthe material where a seam is to be formed during a cycle of operation bythe sewing machine, the needle is actuated to perform the cycle ofoperation, and after a predetermined number of stitches for forming aseam have been made in the material the needle and accordingly, themachine automatically stops its operation whereupon the presser foot israised to its predetermined upper inoperative or ready-for-operationposition and in response to the upward movement of the presser foot thethread cut-oft blade is actuated to cut the thread off.

The present invention improves the above-mentioned conventional cyclicsewing machine by eliminating the disadvantages inherent in this type ofsewing machine. According to the present invention, crank mechanisms arerespectively provided on two shafts which are adapted to intermittentlyrotate through spring clutches in response to the energizing anddeenergizing of magnetic devices. The crank mechanisms are respectivelyconnected to the machine shut-off mechanism and the presser foot controlmechanism, said magnetic devices being adapted to be energized anddeenergized in response to the closing and opening of pedal-actuatedswitches, as well as switches operative in response to the rotationalmovement of the shaft associated with said presser foot controlmechanism and switches or relays associated with said machine shutoffmechanism, whereby the presser foot can be moved between the loweredoperative position and the upper raised ready-for-operation position.When tripped, the shut-off mechanism can actuate the machine to performa cycle of operation. The presser foot is adapted to be held in saidraised ready-for-operation position when the sewing machine needle isheld in a predetermined raised inoperative position above the materialto be sewn after a cycle of operation by the machine.

One object of the present invention is to provide a novel sewing machinewhich can effectively eliminate the defects inherent in the prior artcyclic sewing machines as described above.

Another object of the present invention is to provide a novel cyclicsewing machine in which when manually operated, the foot pedal operatesswitches associated with the shut-off mechanism and the presser footcontrol mechanism whereby the presser foot is lowered to itspredetermined material holding-down position and imrnediately after thepresser foot has been lowered to the holding-down-position the machineis actuated.

A further object of the present invention is to provide a novel sewingmachine in which the presser foot can be easily and precisely alignedwith a portion of the material where a seam is to be formed.

A still further object of the present invention is to provide a novelcyclic sewing machine which does not require skilled personnel foroperating the machine.

The above and other objects and advantages of the present invention willbe more readily apparent to those skilled in the art from the followingdescription when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view ofa preferred form of a control mechanism for a cyclic sewing machineaccording to the present invention with portion broken away and themachine table thereof shown in section;

FIG. 2 is an end elevational view as seen substantially in the directionof IIII of FIG. 1;

FIG. 3 is a bottom plan view of said control mechanism for a cyclicsewing machine shown in FIG. 1;

FIG. 4 is a fragmentary cross-sectional view taken substantially alongthe line VIIV' or IV"IV' of FIG. 3 showing the spring clutch mechanismassociated with the presser foot drive shaft or the needle actuatingshaft;

FIG. 5 is an exploded perspective view of the spring clutch mechanismshown in FIG. 4;

FIG. 6 is a fragmentary cross-sectional view taken substantially alongthe line VI-VI of FIG. 3;

FIG. 7 is a fragmentary cross-sectional view taken substantially alongthe line VIIVII' of FIG. 3;

FIGS. 8 and 9 are schematic views illustrating the relationship betweenthe presser foot support and drive shaft and the associated springclutch mechanism and showing them in different operative positions,respectively;

FIG. 10 is a schematic view illustrating the relationship between theneedle actuating shaft and the associated spring clutch mechanism; and

FIG. 11 is a circuit diagram of the control mechanism of said cyclicsewing machine.

The control mechanism of the present invention is particularly adaptedto be used with a cyclic sewing machine of the type disclosed in US.Patent 2,721,526 to Ivanko, to which reference is made for details ofthe sewing machine per se.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to theaccompanying drawings and more particularly to FIGS. 1 through 3 thereofin which a preferred embodiment of the present invention is illustrated,the control mechanism body 2 for the novel cyclic sewing machine issecured by means of set screws 3 to the underside of the machine table 1on which the sewing machine (not shown) is mounted in the known manner.The control mechanism body 2 includes four pairs of bearings 4 and 4, 5and 5, 6 and 6 and 7 and 7', the two bearings in each pair beinglaterally spaced from each other. The control mechanism body 2 furtherincludes individual bearings 8 and 9.

The first pair of bearings 4 and 4' rotatably support a prime movershaft 12 at the opposite ends of the shaft and the shaft has a pulley 10secured at one extreme end thereof adjacent to the bearing A, A worm 11is fixedly mounted on the prime mover shaft 12 at a point setween theopposite ends of the shaft. The pulley 10 is adapted to transmitcontinuous rotational movement from a suitable conventional prime mover(not shown) through a conventional transmission means such as an endlessbelt (not shown) to the shaft 12.

The second pair of bearings 5 and 5 rotatably support intermediate shaft15 at the opposite ends thereof and the axis of the intermediate shaft15 lies above and intersects at right angles with the axis of the primemover shaft 12. The intermediate shaft 15 has a worm gear 13 and a screwgear 14 at spaced intervals therealong and secured thereto between theopposite ends of the shaft and the worm gear 13 meshes with the worm 11on the prime mover shaft 12.

The fourth pair of bearings 7 and 7' rotatably support a presser footdrive shaft 16 at the opposite ends of the shaft and the presser footdrive shaft extends in the same plane and parallel to the intermediateshaft 15. The presser foot drive shaft 16 has a crank 18 secured to oneextreme end thereof adjacent to the bearing 7, the crank 18 beingprovided with a outwardly projecting crank pin 17, and laterally spacedswitch cams 19 and 20 are secured to the shaft 16 between the oppositeends thereof. The presser foot drive shaft 16 further has a springclutch mechanism 21 secured thereto at a position laterally spaced fromthe switch cam 19. The construction and operation of the clutchmechanism will be described in detail hereinafter. A helical gear 22 ismounted on the presser foot drive shaft 16 for free rotational movementthereon. The helical gear 22 constitutes part of the spring clutchmechanism 21 and meshes with the screw gear 14 on the intermediate shaft15.

The individual bearing 8 supports a presser foot drive plate 23 in sucha manner that the plate can pivot about a pivot pin 24. The drive plate23 is provided with an elongated slot 27 into which the crank pin 17 onthe crank 18 associated with the shaft 16 extends and the crank pin 17is slidable along the walls of the slot. As shown in FIG. 2, the lowerend of a chain 26 is attached to the left end of the presser foot driveplate 23, the upper end of the chain 26 being connected to the presserfoot operating mechanism (not shown) of the sewing machine. Chain 26corresponds to chain 17 in said Patent 2,721,526. The lower end of aspring 28 is anchored to the right end of the presser bar drive plate 23(FIG. 2), the upper end of the spring 28 being suitably anchored to thecontrol mechanism body 2. The strength of the spring 28 is sufiicient'tocounterbalance the force of the spring (not shown) of the presser footmechanism for holding down material to be sewn by the sewing machine.When the crank pin 17 is in the raised position as shown in FIG. 2, thepresser foot (not shown) is in its predetermined lowered operative ormaterial holding-down position and when the crank pin 17 is in thelowered position, the presser foot is in its predetermined raisedinoperative or ready-foroperation position.

The third pair of bearings 6 and 6' rotatably support a needle actuatingshaft 29 the axis of which extends above and parallel to the axis of theprime mover shaft 12 and lies above and intersects at right angles withthe axis of the intermediate and presser foot shafts 15 and 16,respectively. The needle actuating shaft 29 has a crank 31 secured toone extreme end thereof adjacent to the bearing 6, the crank 31 beingprovided with an outwardly extending crank pin 30, and a second springclutch mechanism 32 is fixedly mounted on the needle actuating shaft 29between the opposite ends thereof. A screw gear 33 which meshes with thescrew gear 14 on the intermediate shaft 15 is mounted on the needleactuating shaft 29 for rotational movement thereon. The screw gear 33constitutes part of the associated clutch mechanism 32.

The other individual bearing 9 pivotally supports a needle actuatingplate 34 substantially in the center theref y m a s of a. ste p d screw35 which serves a the fulcrum of the plate. The needle actuating plate34 is bifurcated at one end as shown at reference numeral 36 (FIG. 1)into which bifurcation the crank pin 30 on the crank 31 associated withthe shaft 29 extends for slidable movement between the prongs of thebifurcated end. The other end of the needle actuating plate 34 has thelower end of a chain 66, which is similar to the chain 26 of the presserfoot drive plate 23, secured thereto and the upper end of the chain 66is connected to the shut-off mechanism (not shown) of the sewingmachine. Chain 66 corresponds to chain 64 in said Patent 2,721,526. Whenthe crank pin 30 is moved to the upper position as a result ofrotational movement of the crank 31 on which the pin is mounted, theneedle and accordingly, the sewing machine is actuated for a cycle ofsewing operation.

The above-mentioned spring clutch mechanisms 21 and 32 mounted on thepresser foot drive shaft 16 and needle actuating shaft 29, respectively,are substantially identical with each other in construction except forone portion thereof, and accordingly, the construction and operation ofonly the spring clutch mechanism 21 will be described in detail withreference to FIGS. 4, 5 and 6 and the portion of the other spring clutchmechanism 32 different from the corresponding portion of the springclutch mechanism 21 will be described with reference to FIG. 7.

Referring now to FIGS. 4, 5 and 6, the helical gear 22 freely rotatablymounted on the presser foot drive shaft 16 constitutes part of thespring clutch mechanism 21.

The helical gear 22 is provided at one end thereof with successivelysmaller diameter portions 37 and 38 so as to have a steppedconfiguration and an abutment member 43 having the same inner diameteras that of the gear 22 is fixedly mounted on the shaft 16 by means of atransverse pin 44.

The abutment member 43 is also provided at the end adjacent to thestepped end of the gear 22 with successively smaller diameter portions39 and 40 having the same inner and outer diameters as the reduceddiameter portions 38 and 37, respectively, so as to form a member with astepped configuration. The abutment member 43 has two integral pawls 41and 42 at two angularly spaced points on the periphery thereof and thepawls are directed in diametrically opposite directions to each other.

A split adjusting member 47 having an annular inner portion 48 isreleasably mounted on the reduced diameter portion 40 by means of theinner portion 48 which has the same inner diameter as the outer diameterof the reduced diameter portion 40 of the abutment member 43. Theadjusting member is further provided with a reduced diameter portion orboss 45 and opening 46 which is radially aligned with the axis of themember. A screw 49 extends transversely of the opening 46 so as toadjustably secure the adjusting member 47 against the reduced diameterportion 40 of the abutment member 43.

A clutch .member 52 is loosely mounted around the reduced diameterportion 37 of the helical gear 22 and the reduced diameter portion 45 ofthe adjusting member 47 and has two angularly spaced pawls 50 and 51 onits periphery. The orientation of the pawls 50 and 51 is diametricallyopposite to that of the pawls 41 and 42 on the abutment member 43 andthese pawls 50 and 51 also direct in diametrically opposite directionsto each other. However, the angular displacement between the pawls '50and 51 is the same as that between the pawls 41 and 42. The clutchmember 52 has an axial bore 53 whose inner diameter is larger than theouter diameter of the adjacent reduced diameter portions 38 and 39 ofthe helical gear 22 and abutment member 43 and accordingly, the axialbore 53 and the reduced diameter portions 38 and 39 define an annularspace 54 therebetween. The inner periphery of the axial bore 53 isprovided with a pin 55 which extends radialy toward the axis of theannular space 54.

A spring 57 in the form of a coiled fiat spring steel strip is looselydisposed in the annular space 54 with one end 56 thereof bent radiallyand outwardly into and anchored in the opening 46 of the adjustingmember 47 and the free end of the spring is adapted to abut against thepin 55 of the clutch member 52.

As shown in FIG. 6, the spring clutch mechanism 21 is adapted tocooperate with a detent piece 58 which is pivoted to the frame (notshown) of the clutch mechanism in a known manner and the detent piece isadapted to abut against either one of the two pawls 41 and 42 on theabutment member 43 so that the abutment .member is allowed tointermittently rotate in the direction of the arrow or counterclockwisedirection, but is prevented from rotating in the clock-wise direction asseen in FIG. 6.

The spring clutch mechanism 21 is further adapted to cooperate with amagnetic device 59 which has an armature 60 adapted to engage either oneof the pawls 50 and 51 on the clutch member 52. The magnetic device isso designed that when the device in its deenergized position itsarmature 60 is caused to engage one of the pawls 50 and 51 so as toprevent the clutch member 52 from rotating in the direction of the arrowas seen in FIG. 6, but when the device is in its energized position itsarmature 60 is caused to disengage from the engaged pawl 50 so as toallow the clutch to rotate in the direction of the arrow. The armature60 of the magnetic device 59 is normally urged against either one of thepawls 50 and 51 on the clutch member 52 by means of a spring 61 having astrength less than the attractive force of the device 59 and the otherend of the spring is suitably anchored to a conventional anchoring means(not shown).

As mentioned above, the spring clutch mechanism 32 is substantially thesame as the first spring clutch mechanism 21 except that the abutmentmember 43 is provided provided with only one pawl which is shown atreference 41 in FIG. 7, instead of two pawls as in the case of theclutch mechanism 21 and the clutch member 52 is also provided withonlyone pawl which is shown at reference numeral 50' instead of two pawls asin the case of the clutch mechanism 21. The orientation of the abutmentmember pawl 41' is the same as that of the corresponding pawl 41 on theabutment member 43 while the orientation of the pawl 50 is also the sameas that of the corresponding pawl 50 on the clutch member 52. The otherparts and arrangement of the second spring clutch mechanism 32 areidentical with those of the spring clutch mechanism 21 and thecorresponding parts of the second spring clutch mechanism are indicatedwith the same reference numerals with primes added thereto in FIG. 7.

The positions and orientations of the pawls on the abutment member 43and clutch member 52 for the presser foot drive shaft 16 are as shown inFIG. 6, and when the pawl 50 on the clutch member 52 is in engagementwith the armature 60 of the magnetic device 59, the pawl 41 on theabutment member 43 is also in engagement with the detent piece 58 andunder these conditions the position of the crank pin 17 on the crank 18associated with the presser foot drive shaft 16 is as shown with thecircular broken line in FIG. 8 in which the presser foot (not shown) isin its predetermined lowered operative position for holding down thematerial to be sewn by the sewing machine (not-shown).

When the pawl 51 on the clutch member 52 is in engagement with thearmature 60, the pawl 42 on the abutment member 43 is also in engagementwith the detent piece 58 and under these conditions the position of thecrank pin 17 on the crank 18 is as shown with the circular broken linein FIG. 9 in which the presser foot is in its predetermined upperinoperative position or ready-foroperation position.

The positions and orientations of the pawls on the abutment member 43'and clutch member 52' associated with the needle actuating shaft 29 areas shown in FIG. 7, and when the sole pawl 50 on the clutch member 52'is in engagement with the armature 60 of the magnetic device 59, thesole pawl 41 on the abutment member 43' is also in engagement with thedetent piece 58', and under these conditions, the position of the crankpin 30 on the crank 31 associated with the needle actuating shaft 29 isas shown with the circular broken line in FIG. 10 in which the shut-offmechanism is not yet tripped, but thereafter when the crank 31 andaccordingly, the crank pin 30 is moved to the predetermined raisedposition as the shaft 29 rotates, the shut-off mechanism is tripped topermit the needle and accordingly, the sewing machine to beginoperation.

As shown in FIG. 3, switches 62 and 63 are provided so as to cooperatewith and to be actuated by the switch cams 19 and 20, respectively andthe cams are adapted to alternately actuate the respectively associatedswitches as the presser foot drive shaft rotates. The relationshipbetween the switch cams 19, 20 and the associated switches is sodesigned that when the presser foot (not shown) is in its predeterminedlowered operative position for holding down the material to be sewn andthe presser foot drive shaft 16 and associated parts are as shown inFIG. 8, the cam 19 closes the associated switch 62 while the cam 20opens the associated switch 63. On the other hand, when the presser footis in its predetermined raised inoperative or ready-for-operationposition and the presser foot drive shaft 16 and associated parts are asshown in FIG. 9, the cam 19 opens the associated switch 62 while the cam20 closes the switch 63.

FIG. 11 shows the electric circuit for the control mechanism of thenovel cyclic sewing machine and in this circuit, a switch 64 is providedwhich is associated with the shut-off mechanism, such as described insaid Patent 2,721,526, which is adapted to actuate the sewing machinewhen the shut-off mechanism is tripped and to hold the needle in itspredetermined raised inoperative position when the shut-off mechanism isactuated.

The switch 64 is so designed that when the needle is positively held inits predetermined inoperative raised position, the switch is closed, butas soon as the sewing machine is actuated for sewing operation, theswitch 64 is opened and maintained in its open state during the sewingoperation of the machine. Switch 64 can be actuated by arm 38 shown insaid Patent 2,721,526 to be closed when the arm 38 is the position ofFIG. 3 of the patent and the sewing machine is running, and open whenthe arm 38 is in the FIG. 5 position of the patent, and the sewingmachine is stopped.

The switches 62 and 63 are alternately closed and opened by therespective cams 19 and 20 on the presser foot drive shaft 16, in themanner as mentioned above.

The magnetic device 59 is associated with the spring clutch mechanism 21on the presser foot drive shaft 16 as shown in FIG. 6 and the othermagnetic device 59' is associated with the spring clutch mechanism 32 onthe needle actuating shaft 29 as shown in FIG. 7.

Switches P1, P2 and P3 are provided in the circuit and adapted to beclosed and opened by manipulation of the manual foot pedal of the sewingmachine. The switches P2 and P3 are so mechanically interlocked thatwhen one of the two switches is closed or opened the other switch isopened or closed, respectively, and the switches P1 and P2 are alsointerlocked in the same manner as in the case of the switches P2 and P3.The switches P1, P2 and P3 may be sequentially manipulated in the ordermentioned, for example by fully depressing the foot pedal, or only theswitch P1 may be manipulated independently of the other two switches,for example by partially depressing the foot pedal.

Relays R1 and R2 are also provided in the circuit and when these relaysare energized or deenergized a plurality of switches Rl-l and R12 andR2-1, R22, R23 and R2-4, respectively, are closed or opened accordingly.

When the relays T1 and R2 are deenergized the switches assume thepositions shown in the solid lines, respectively, in FIG. 11 and whenthe two relays R1 and R2 are energized their associated switches assumethe positions shown with the broken lines in the same figure.

Reference numeral 65 designates a conventional lamp which is lighted upor out by a switch P4. The switch P4 is closed only when the automaticthread breakage detection device (not shown) has detected a threadbreakage and the closed switch P4 lights up the lamp 65 to indicate tothe operator the necessity for interrupting the operation of the sewingmachine.

The solid line position of the various switches in the circuit of FIG.11 show the conditions in which the sewing machine is not operated, thepresser foot is lowered to its predetermined operative position forholding down the material to be sewn, the switches P1 and P2 are notactuated by the foot pedal and no current is flowing through thecircuit.

In operation, when the prime mover (not shown) is energized, continuousrotational movement is transmitted from the mover through theconventional transmission means (not shown) to the pulley 10 to rotatethe pulley is the direction of the arrow in FIG. 1 and the rotation ofthe pulley 10 in turn continuously rotates the prime mover shaft 12 onwhich the pulley is fixedly mounted in the same direction.

As the shaft 12 rotates the worm 11 fixedly mounted on the shaft isrotated and the worm in turn rotates the intermediate shaft 15 and thescrew gear 14 on the shaft by virtue of meshing engagement between theworm 11 and screw gear 14 fixedly mounted on the intermediate shaft inthe counter-clockwise direction as seen in FIG. 2. In this case, thehelical gear 22 meshing with the screw gear 14 and constituting part ofthe spring clutch mechanism 21 rotates about the presser foot driveshaft 16 and the screw gear 33 meshing with the gear 14 and constitutingpart of the spring clutch mechanism 32 also rotates about the needleactuating shaft 29.

The rotational direction of the helical gear 22 is counterclockwise asseen in FIG. 6 and the reduced diameter portion 38 integral with thegear also rotates in the same direction as the gear 22, but when themagnetic device 59 is not energized its armature 60 abuts against thepawl or 51 on the clutch member 52 and the free end of the spring 57abuts against the inwardly projecting pin 55 so that the spring can beprevented from following the rotating helical gear 22, and accordingly,the helical gear 22 is allowed to rotate about the shaft 16independently of the clutch member 52 and abutment member 43.

When the magnetic device 59 is energized to magnectically attract thearmature so as to disengage the pawl from the associated pawl on theclutch member 52, the clutch member will be permitted to rotate in thecounterclockwise direction as seen in FIG. 6 and as a result, the pin 55releases the free end of the spring 57. In this case, due to frictionalcontact between the reduced diameter portion 38 of the continuouslyrotating helical gear 22 and the inner periphery of the spring 57 thespring is caused to be firmly wound on the outer periphery of thehelical gear 22 and of the reduced diameter portion 39 of the abutmentmember 43 (see FIG. 4) so as to be firmly engaged with the reduceddiameter portions. Accordingly, the rotational movement of the helicalgear 22 causes rotation of the presser foot drive shaft 16 which issecured to the abutment member 43 by means of the pin 44.

On the other hand, when the magnetic device 59 is deenergized thearmature 60 thereof is urged toward the associated pawl on the clutchmember 52 to resume its engagement with the clutch member 52 by theforce of the spring 61 having the lower end thereof secured to thearmature whereupon the pin 55 is held in the predetermined position soas to be engaged by the free end of the spring 57 'whereby the spring 57is prevented from following the rotating helical gear 22. Therefore, thehelical gear 22 and the abutment member 43 which are now connected toeach other by the spring 57 will be separated from each other wherebythe presser foot drive shaft 16 ceases to rotate and the helical gear 22resumes independent rotational movement about the now stationary shaft16,

As mentioned above, the spring clutch mechanism 32 on the needleactuating shaft 29 (FIG. 7) has the substantially same construction asthat of the corresponding mechanism 22 on the presser foot drive shaft16 and the operation of the mechanism 32 is substantially the same asthat of the first mechanism 21.

To describe the operation of the spring clutch mechanism 32 briefly,when the associated magnetic device 59 is in its deenergized positionand its armature 60' is in engagement with the sole pawl 50 on theclutch member 52' as shown in FIG. 7, the helical gear 33 is allowed torotate about the needle actuating shaft 29. On the other hand, when themagnetic device 59 is energized and the associated armature 60' isdisengaged from the associated pawl 50' on the clutch member overcomingthe force of the spring 61' secured to the armature, the helical gear 33and the actuating shaft 29 will be caused to rotate in unison in thecounter-clockwise direction as seen in FIG. 7.

After a cycle of operation has been completed, the magnetic device 59'is again deenergized and its armature 60 is urged to engage the pawl 50'on the clutch member 52' by the force of the spring 61 whereupon thespring clutch mechanism 32 is tripped to cause the actuating shaft 29 tocease its rotation and to allow the helical gear 33 to rotate freelyabout the shaft 29 again.

As the presser foot drive shaft 16 rotates in the clockwise direction asseen in FIG. 2, the crank 18 fixedly mounted on the shaft 16 and havingthe crank pin 17 thereon rotates in the same direction. In this case,the movement of the crank pin 17 between its predetermined upper andlower limits controls the movement between the upper inoperativeposition and lower operative position of the presser foot (not shown) bymeans of the drive plate 23 and chain 26 secured thereto.

As the needle actuating shaft 29 rotates in the clockwise direction asseen in FIG. 1, the crank 31 fixedly mounted on the shaft 29 and havingthe crank pin 30 thereon rotates in the same direction. In this case,the movement of the crank pin 30 between its predetermined upper andlower limits controls the movement of the needle (not shown) between theupper inoperative position and lower operative position by means of theactuating plate 34 and chain 66 secured thereto.

To describe the manner in which the novel cyclic sewing machine isactually operated for a sewing operation, when the needle actuatingshaft 29 and the crank pin 30 are in the positions as shown in FIG. 1,the cyclic sewing machine is in its inoperative condition in which thepresser foot drive shaft 16 and the crank pin 17 assume the positions asshown in FIG. 2 with the presser foot lowered on the material to be sewnand holding down the same against the machine table. Under thiscondition, the sole pawl 50 on the clutch member 52' associated with theneedle actuating shaft 29 is engaged by the armature 60' of the magneticdevice 59' which is in the deenergized state as shown in FIGS. 7 and 10.Also under this condition, the positions of the switch cams 19, 20 andthe clutch pawls 50 and 51 associated with the presser foot drive shaft12 are as shown in FIGS. 6 and 8 in which the switch cam 19 closes theassociated switch 62 while the switch cam 20 opens the associated switch63 and the pawl 50 is engaged by the armature 60' of the magnetic device59 which is now in the deenergized state. The positions of the variousswitches in the electric circuit under this condition are indicated withthe solid lnes.

When current is caused to flow through the electric circuit of FIG. 11,the current flows through the switch 64, the relay switch R11, theswitch 63, the relay switch R2-1 and the switch P1 to energize themagnetic device 59 whereby the armature 60 associated with the magneticdevice is disengaged from the pawl 50 on the clutch member 52 whereuponthe spring clutch mechanism 21 is 0perated to rotate the associatedpresser foot drive shaft 16 in the clock-wise direction as seen in FIG.2.

The shaft 16 continues to rotate about until the switch cam 19 on theshaft opens the switch 62 and the switch cam 20 closes the switch 63 tothe position indirated with the broken line in the circuit of FIG. 11whereupon the circuit to the magnetic device 59 is broken off todeenergize the device and to armature 60 engages the pawl 51 on theclutch member 52, and then the shaft 16 ceases to rotate. According,when the shaft 16 has completed its 150 rotation the crank pin 17 hasmoved from the position of FIG. 8 to that of FIG. 9 and the presser foothas been raised from the lower operative position to the upperinoperative or ready-for-operation position. Under this condition, theswitches 62 and 63 have been moved to the positions indicated with thebroken lines in FIG. 11.

With the presser foot held in the raised position as mentioned justabove, the material to be sewn is placed on the machine table below thepresser foot and thereafter the switch P1 is depressed to the brokenline position to close the switch whereupon current flows through theswitch 64, the relay switch R1-1, the switch 63 (now in the broken lineposition) and the switch P1 to energize the magnetic device 59.

The energized magnetic device 59 magnetically attracts its armature 60to disengage the armature from the now engaged pawl 51 on the clutchmember 52 whereupon the spring clutch mechanism 21 is operated to rotatethe presser foot drive shaft 16 in the clock-wise direction as seen inFIG. 2. The shaft 16 continues to rotate about 210 until the switch cam19 closes the switch 62 while the switch cam 20 opens the switch 63 tothe solid line position of FIG. 11 whereupon the circuit to the magneticdevice 59 is broken off to deenergize the device and to urge theassociated armature 60 to engage the pawl 50 on the clutch device 52 andthen the shaft ceases to rotate.

The rotation of the presser foot drive shaft 16 through 210 as mentionedabove moves the crank pin 17 from the position of FIG. 9 to that of FIG.8 and lowers the presser foot from the upper inoperative orready-for-operation position to the lower operative or material holdingdown position by means of the presser foot drive plate 23 and the chain26 secured thereto.

In this case, if it has been found that the material is not disposed ina proper sewing position on the machine table, the switch P1, which isnow in the broken line position, is moved to the solid line position andcurrent is allowed to flow through the magnetic device 59 to energizethe device. The energized magnetic device operates in the same manner asmentioned above and the crank pin 17 is moved from the position of FIG.8 to that of FIG. 9 whereby the presser foot is raised to the upperinoperative position and held there and the position of the material isadjusted to a proper sewing position while the presser foot is held inthe raised position. With the presser foot held in this upperinoperative position, the switch 63 is closed or in the broken lineposition of FIG. 11, the switch 62 is in open or in the broken lineposition of FIG. 11 and the switch P1 is in the solid line position ofFIG. 11.

After the material to be sewn has been positioned in the proper sewingposition on the machine table below the presser foot, the switch P1 isagain depressed down to the broken line position whereupon the magneticdevice 59 is energized in the manner as described above and the crankpin 17 is moved from the position of FIG. 9 to that of FIG. 8 so as tolower the presser foot to the lower operative position for holding downthe material and at the same time the switch 62 is closed to the solidline position and the switch 63 is opened to the solid line position ofFIG. 11, respectively.

Thus, it will be understand that when the material to be sewn is not inthe proper sewing position the presser foot can be raised to the upperinoperative position and the position of the material can be adjustedwith the presser foot held in the raised inoperative position.

After the position of the material has been adjusted, the switch P1which has been depressed to the broken line position of FIG. 11 isfurther depressed so as to move the associated switches P2 and P3 to thebroken line positions of FIG. 11 whereupon current is caused to flowthrough the switches 64, P2 and 62 (now in the solid line position) toenergize the relay R1. The energized relay R1 moves the switches Rl-land R1-2 to the broken line positions of FIG. 11. When the switch Rl-lis moved to the broken line position current is caused to flow throughthe switches 64 and R1-1 (now in the broken line position) to energizethe magnetic device 59' whereby the armature 60' of the device 59 isdisengaged from the pawl 50' on the clutch 52' whereupon the springclutch mechanism 32 is operated to cause the needle actuating shaft 29to rotate in the clockwise direction as seen in FIG. 1.

When the crank pin 30 on the crank 31 associated with the shaft 29 ismoved to the predetermined upper limit of its stroke as the shaft 29rotates in the above direction, the crank pin 30 trips the shut-offmechanism (not shown) by means of the needle actuating plate 34 andchain 66 attached thereto so as to actuate the needle and accordingly,the sewing machine sewing operation with the shutoff mechanism held inits tripped position. The control mechanism of the invention thusinitiates the sewing machine operation, and further drive is carried outby the sewing machine itself. Simultaneously, the switch 64 is opened tothe broken line position of FIG. 11 to break off the circuit to therelay R1 to deenergize the relay and move the switches R11 and R1-2 tothe solid line posi tions thereby to break off the circuit to themagnetic device 59 to deenergize the device. Accordingly, the magneticdevice 59' is deenergized before the needle actuating shaft 29 hascompleted a complete rotation of 360 and the armature 60' of themagnetic device 59' is moved to the upper position and engages again thepawl 50' on the clutch member 52' which has just completed a completerotation. Thereby the crank pin 30 and the needle actuating plate 34stop in the positions as shown in FIGS. 1 and 10, respectively.

The reason for which the switch R1-2 is closed in the broken lineposition is that the closed switch R12 completes a self-holding circuitfor the relay R1 which prevents any trouble which may occur if theswitch P2 was depressed for a very short period of time. That is, if bythe actuation of the relay R1 the switch R1-1 is moved to the brokenline position and the switch P2 is opened before the magnetic device 59'is energized, without the holding circuit the relay R1 would bedeenergized and return the switch R11 to the initial solid line positionso that the magnetic device 59 would not be energized.

After the operator has confirmed that the presser foot has beensufficiently lowered to the material holding-down position and thesewing machine has been set in operation, he releases the switches P1and P2 (P3) by releasing the foot pedal which has been previouslydepressed. Under this condition, since the presser foot is now in itslowered operative position (FIG. 8), the switches 62 and 63 are then inthe solid line positions of FIG. 11. And since the sewing machine hasbeen set in operation, the switch 64 is in the broken line position(open), the released switches P1 and P2 (P3) are in the solid linepositions, and the switches R1-1 and R1-2 are in the solid line positionwith the relay R1 held in the inoperative position.

Thus, after the cyclic sewing machine has completed a cycle of operationby forming a predetermined number of stitches on the material to be sewnand the needle has been raised to the predetermined upper inoperativeposition and set there by the actuation of the shut-off mechanism, theswitch 64 is closed to the solid line position whereupon current iscaused to flow through the switches 64, Rl-l, 63, R21 and P1 to energizethe magnetic device 59 whereby the presser foot is caused toautomatically rise to the predetermined upper inoperative position.

In other words, the energized magnetic device 59 magnetically attractsthe armature 60 to disengage the same from one of the pawls and 51 ofthe clutch member 52 whereupon the spring clutch mechanism 21 isoperated to rotate the presser foot drive shaft 16 in the clockwisedirection as seen in FIG. 2. The presser foot drive shaft 16 continuesto rotate about 150 until the switch cam 19 opens the switch 62 whilethe switch cam 20 closes the switch 63 to the broken line position inFIG. 1 to break off the circuit to the magnetic device 59 to deenergizethe device. The armature 60 associated with device 59 is caused toengage the other pawl on the clutch member, and then the shaft ceases torotate. Thus, as the shaft 16 rotates about 150 as mentioned above, thecrank pin 17 moves from the position of FIG. 8 to that of FIG. 9 whileraising the presser foot from the lower operative position topredetermined the upper inoperative position by means of the drive plate23 and chain 26 secured thereto and at the same time the switches 62 and63 are moved to the broken line positions of FIG. 11.

As mentioned above, when it is desired or necessary to adjust theposition of the material to be sewn so as to dispose a portion orportions of the material where a predetermined number of stitches are tobe formed in a proper position relative to the presser foot, the switchP1 is operated to raise the presser foot to the upper inoperativeposition and the position of the material is adjusted with the presserfoot held in the raised position, and after the material has beenproperly positioned, the switch P2 (P3) is closed to actuate the sewingmachine. After it has been confirmed that the sewing machine has beenset in motion, the switches P1 and P2 P3) are returned to the initialpositions.

If the thread breaks during the operation of the sewing machine, theswitch P4 associated with the thread breaking detection device (notshown) is automatically energized to close to the dotted line positionof FIG. 11 and current is caused to flow through the switches P3 and P4to energize the relay R2 and the energized relay R2 in turn moves theswitches R21, R22, R23, and R24 to the closed positions in FIG. 11.

The switch R21 is adapted to break the circuit to the magnetic device 59so as not to energize the device even if the switch 64 is closed after acycle of operation by the sewing machine. The switch R23 is adapted tocause the relay R2 to self-hold and the switch R24 is adapted to lightup the lamp 65 so that the operator will be given a visual warning ofsuch breakage of the thread.

The function of the switch R21 will now be described. Since the switchR21 is opened before a cycle of the sewing operation is completed andthe magnetic device 59 is not energized even if the switch 64 is closedafter the cycle of the sewing operation, the presser foot can not riseto the upper inoperative position after the cycle of operation andremains in the lower operative or material holding-down position and thesewing machine ceases operation with the presser foot held in the lowerposition.

Under this condition, since the sewing machine is not in its normaloperation position, the positions of the various switches of theelectric circuit of FIG. 11 will be such that the switch 64 is in thesolid line position, the switches 62 and 63 are in the solid linepositions because the press er foot is held in the lowered position, theswitches R21, R22, R23 and R24 are in the broken line positions becausetheir relay R2 is energized, the switches P1 and P2 (P3) are in thesolid line positions because the manual pedal has been released.

If the sewing machine is manually turned back to the same position inwhich the thread broke and then the broken ends of the thread are tiedtogether, thereafter the switch P4 will be opened to the solid lineposition. But the relay R2 is self-holding by means of the switch R23,and the relay maintains its energized condition. Thereafter, when theswitch P1 is depressed the switch assumes the position indicated withthe broken line, but since the switch 63 is in the solid line position,the magnetic device 59 is not energized and the presser foot is held inthe lowered operative position.

Furthermore, when the switch P2 (P3) is depressed to the broken lineposition, then the switch P2 energizes the relay R1 to move the switchRl-l to the broken line position whereby the magnetic device 59' isenergized to actuate the sewing machine in the manner mentioned aboveand the switch P3 breaks ofi the circuit to the relay R2 to deenergizethe relay and accordingly, the switches R21, R22, R23 and R2-4 are movedto the solid line positions. The switch R2-3 releases the relay R2 fromits function of self-holding and the switch R2-4 opens to deenergize thelamp 65 and subsequently the switches P1 and P2 (P3) are opened byrelease of the foot pedal after the sewing machine has resume itsoperation to move the switches to the solid line positions. Accordingly,the sewing machine can resume sewing operation from the, point on thematerial where the thread broke down and when the machine has completedthis particular cycle of sewing operation which was once interrupted dueto thread breakage. The needle is then raised to the predeterminedinoperative position and held there whereupon the switch 64 is closed toenergize the magnetic device 59 so as to raise the presser foot to thepredetermined upper inoperative or ready-for-operation position in themanner as mentioned above.

When the sewing machine is left inoperative for a fairly long period oftime such as the period from the time at -.which one days work on thesewing machine has ended to the time at which the next days work starts,since the presser foot is left in its raised position for such a longtime, the spring which is adapted to urge the presser foot against thematerial to be sewn for holding the material down is left in itsextended state for the long time. The spring can easily become fatiguedand there is the possibility that the holding-down force of the presserfoot may fluctuate.

In order to eliminate such a difliculty, the following electric circuitis established. That is, when a cycle of the sewing operation has beencompleted, since the sewing machine still stands in the predeterminedinoperative position and the presser foot is held in the upperinopera'tive position (FIG. 9) a circuit is so established such thatonly the switches 62 and 63 associated with the presser foot drive shaft16 (in the material holding-down position) among the various switchesshown in FIG. 11, main the broken line positions and all the otherswitches are in the solid line positions.

With the electric circuit established in this way, when the switch P4,which is responsive to the automatic thread breakage detection device,is closed to the broken line position, current is caused to flow throughthe switches P3 and P4 to energize the relay R2 so as to move thswitches R21, R22, R23 and R2-4 which are associated with the relay R2to the broken line positions. Thereupon the switch R2-1 interrupts thecircuit to the magnetic device 59, the switch R23 causes the relay R2toiself-hold and the switch R2-4 lights the lamp 65 up. And when theswitch R22 is moved to the broken line position, simultaneously currentis allowed to flow through the switches 64, R1-1 and 63 (in broken lineposition) to energize the magnetic device 59 so as to attract theassociated armature 60 to separate the same from the pawl 51 on theclutch member 62. Thereupon spring clutch mechanism 21 is operated torotate the presser foot drive shaft 16 in the clock-wise direction asseen in FIG. 2.

The drive shaft 16 continues to rotate about 210 until the switch cam 19closes the switch 62, the switch cam 20 opens the switch 63 to the solidline position in FIG.

11, the magnetic device 59 is deenergized because both the circuitsthereto are interrupted and the armature 60 engages the other pawl 50 onthe clutch member 52, and then the shaft 16 ceases to rotate. As thepresser foot drive shaft 16 rotates in the manner as described justabove, the crank pin 17 on the crank 18 associated with the shaft 16moves from the position of FIG. 9 to that of FIG. 8 and lowers thepresser foot from the upper inoperative or ready-for-operation positionto the lower operative or material holding-down position and hold in thelowered position by means of the presser foot drive plate 23 and chain26 secured thereto.

As is clear from the foregoing description, in the novel cyclic sewingmachine, when the various switches are manipulated by pressing the onlyone pedal down, both the sewing machine shut-off mechanism (whichnormally holds the needle in the predetermined upper inoperativeposition and when tripped, actuates the needle and accordingly, thesewing machine) and the presser foot control mechanism aresimultaneously actuated. As compared with the conventional cyclic sewingmachine, in which the shut-off mechanism and presser foot controlmechanism must be separately operated, requiring complicated operationprocedures and highly trained operators, the novel cyclic sewing machinecan be operated with great ease and simple procedures and reduce fatigueof the operator whereby operation efficiency can be greatly enhanced.

Furthermore, if desired or necessary, only the presser foot can be movedupwardly and downwardly while the other machine parts are keptinoperative, and accordingly, the position of the needle can beprecisely aligned with the material to be sewn by suitably adjusting theposition of the needle relative to that of the material.

In addition, if any thread breakage occurs during a cycle of operation,after a cycle of the sewing operation has been completed forming animperfect seam line on the material, the presser foot can be effectivelyprevented from being raised to the upper inoperative position, andaccordingly, the next cycle of sewing operation can resume at the verypoint on the material where the thread breakage occurred.

Furthermore, the novel cyclic sewing machine is so designed that whenthe thread cutting blade is perated in response to the upward movementof the presser foot and the switch 64 associated with the shut-olfmechanism is closed so as to raise the presser foot only when the needlehas been set in the predetermined upper inoperative position, when theshut-off mechanism gets out of order and the needle fails to rise to thepredetermined upper position, the thread cut-off blade also fails tooperate, and accordingly, the presser foot and the thread cut-off bladewill not intersect each other and breakage and/or damage which will beotherwise inevitable will be prevented.

While one preferred embodiment of the invention has been shown forpurpose of disclosure, other embodiments of the invention as well asmodifications to the disclosed embodiment thereof which do not departfrom the spirit and scope of the invention may occur to those skilled inthe art.

What is claimed is:

1. In a cyclic sewing machine of the type having a shut-oif mechanismoperable to initiate the operation of the sewing machine and to sto thesewing machine with the needle held in its predetermined raised positionafter a cycle of operation of the sewing machine has been completed, afirst pull chain for actuating said shut-off mechanism to start thesewing machine, a presser foot movable between its lowered materialclamping position and its raised ready-for-operation position and asecond pull chain for actuating said presser foot; a control mechanismcomprising a support, a starting shaft rotatably mounted on said supportand having a first crank on one end thereof, a starting lever pivotallymounted on said support and having one end connected with said firstpull chain and the other end coupled with said first crank, a firstspring clutch on said starting shaft, a first electromagnet operativelyassociated with said first clutch to cause said starting shaft to rotatethrough only one revolution each time said first electromagnet isactuated to cause said starting lever to pull said first pull chain tostart the sewing machine, a presser foot drive shaft rotatably mountedon said support and having a second crank secured to one end thereof, anactuation lever pivotally mounted on said support and having one endconnected with said second pull chain and the other end coupled withsaid second crank, a second spring clutch on said presser toot driveshaft, a second electromagnet operatively associated with said secondclutch to cause the presser foot drive shaft to rotate intermittentlyand to stop at two positions during each revolution for moving saidactuation lever to pull and release said second pull chain to cause saidpresser foot to rise and lower between its raised position and itslowered position, and a control circuit connected to said electromagnetsand having manually actuated switch means and shut-off mechanismactuated switch means there-in for energizing said electromagnets forraising and lowering of said pressing foot and for starting operation ofsaid sewing machine by tripping said shut-01f mechanism.

2. A control mechanism as claimed in claim 1 in which the manuallyactuated switch means of said control circuit comprises a first switchin series with said second electromagnet for selectively energizing saidsecond electromagnet for selectively operating said presser foot, and asecond switch in parallel with said first switch and a relay in serieswith said second switch, said first electromagnet being in parallel withsaid second electromagnet and said control circuit having a relay switchin series with said electromagnets for energizing them alternately, saidrelay switch being switched by said relay, whereby when said secondswitch is actuated, said first electromagnet is energized to trip saidshut-off mechanism for starting said sewing machine.

3. A controi mechanism as claimed in claim 2 in which said shut-offmechanism actuated switch means comprises a further switch in serieswith said first and second electromagnets and said second switch fordecnergizing said circuit when said shut-01f means has been tripped foroperating said sewing machine through a cycle of operation.

4. A control mechanism as claimed in claim 2 in which said first andsecond switches are mechanically linked for sequential operation in thenamed order.

5. A control mechanism as claimed in claim 2 further comprising a threadbreakage responsive switch, said sewing machine having a thread breakagedetecting means with which said responsive switch is coupled, a threadbreakage responsive relay in series with said thread breakage responsiveswitch, and relay switches actuated by said thread breakage responsiverelay connected in said circuit with said second electromagnet, saidrelay switches breaking said circuit including said second electromagnetwhen the thread breaks for preventing energization of said electromagnetand rise of the Presser foot.

References Cited UNITED STATES PATENTS 1,006,583 10/1911 Miller 112-672,540,730 2/1951 Hayes 11267 2,722,184 11/1955 Sweet 112-67 2,914,01011/1959 Cohen.

2,928,362 3/1960 Benink et a1 11267 2,967,499 1/1961 Cohen.

3,033,142 5/1962 Winz.

3,332,377 7/1967 Emslie et al 11267 XR H. HAMPTON HUNTER, PrimaryExaminer US. Cl. X.R.

